Mechanical properties of Ti/Mg bicontinuous composite by liquid metal replacement

Abstract

A Ti/Mg composite with bicontinuous microstructure of α-Ti/α-Mg was fabricated using a Ti-Sc precursor's microstructure as a template. A Ti-Sc precursor alloy with α-Ti/α-Sc dual-phase microstructure was immersed in molten Mg, and using differences in chemical interactions between the alloy's components and the metallic melt, only α-Sc of the precursor was replaced by molten Mg. The Ti/Mg composite exhibited an ultimate tensile strength of 308.4 MPa and elongation of 6.8 % by a tensile test. The microstructure elongated in the tensile direction indicates that the α-Ti and α-Mg phases cooperatively deformed and contributed to ductility. The continuous microstructure in the tensile direction of the immiscible phases and the weak interface that does not separate because of geometric constraints may be the reason why the hardness properties of the composite follow the Voigt rule.